Disk Volume Serial Number Changer is a program that can change the serial number of any hard drive. It will NOT change the physical serial of your hard disk, just the internal number that the operating system applies to it.

Serial Port Monitor is a professional tool that every serial driver developer should have nearby. It's primarily used for monitoring and analyzing data traffic incoming or outgoing to a serial RS232 interface.

Serial Port Sniffer ActiveX Control is a versatile component that you can embed into your application to enable it to sniff (monitor) serial ports in the system, meaning that it lets you track all serial port activity and learn which applications are using the particular serial port.